Written by davethetreecenters • May 04 Understanding Organic Material

In the extended and detailed descriptions of our plants, which make the Tree Center unique, we provide more background information and accurate advice than any other on-line nursery. In there you will often find something about using ‘organic material’ when planting, or as mulch over the roots of your plants. We get inquiries about this, and so here we will describe exactly what it is, how you can get it, why it is so important, and how to use it.

What is Organic Material?

First of all, let’s clear up one thing. Although organic materials are almost always used by growers of ‘organic’ foods and plants, there are lots of successful gardeners who use organic material when growing, and then supplement it with chemical fertilizers. Whatever your thoughts one way or the other on ‘organic’ – and we don’t take sides – there is an important place for organic material in every garden if you want the best results from your gardening efforts.

That said, what is organic material anyway?  It’s simple. It is the result of the partial decay of plant parts (leaves for example) or the waste of animals (for example, cow, horse, chicken manure, and also wool and even horns and hoofs). It is what happens when plants die, falling to the ground and being used as food by natural microbes (bacteria and fungi) in the soil. It’s a pretty vital process, otherwise we would be surrounded by dead leaves from fall, 10,000 BC, and every dead animal since then too. The planet would grind to a halt, buried under its own waste and dead, if it wasn’t for the many microbes that eat it for lunch.

Now like some lunches, parts of that waste are easier to get at than other parts, so at first it’s a big party, with all those microbes going to town, eating like crazy and reproducing like crazy too. But after a while, once those leaves or fallen apples no longer look like anything much, the microbes are reduced to ‘picking the bones’, so everything slows down, and what is left is called ‘humus’ (no, not the Lebanese dip). This stuff takes longer to be decomposed, maybe a year, more likely 3 or 4, and maybe ten or more. Humus has some amazing properties when it gets into the soil, and when we say add organic material, what we could say instead is add humus.

What is Organic Material Good For?

This humus does four big things in soil:

  1. As it breaks down humus releases all the minerals that plants need to grow, from nitrogen to potash, plus, very importantly, all the trace elements plants need too. (No vitamins, because plants don’t need them – they make there own from simpler chemicals.) This is the basis of organic growing – feed your plants this way, instead of adding those same minerals from man-made sources. Humus needs to be ‘rich’ – relatively fresh, with lots of fairly easy-to-get-at food in it for microbes – to be able to release enough minerals fast enough for growing vegetables and flowers, although shrubs and trees will usually grow fine on older, less ‘quick-release’ materials.
  2. Humus has lots of chemical ‘pockets’ (technically called ‘cation exchange sites’) that hold minerals that are released, preventing them from washing out of the soil when it rains, or when you water your beds. This is especially true on sandy soils, where organic material is especially important for growing. This feature makes your soil better for growing, since plants can easily get those chemicals out of the pockets when they need them. You will really see the difference, with more rapid growth, bigger leaves and more blooms and fruit.
  3. Because humus comes in ‘bits’ – the tough inner parts of stalks or the fragments of leaf veins, for example, those bits create channels for air and water to pass through the soil, separating fine soil particles -especially clay – and improving drainage (water passage through the soil) and aeration (bringing oxygen to roots, which do need plenty of it, and reducing rots. If you want that magical ‘well-drained soil’ so many plants seem to need, adding organic material to your soil is a great way to get it.
  4. The breakdown of organic material releases gums and resins. These stick tiny soil particles together – clay again – making bigger pieces. This is another way that humus increases drainage and aeration.

You can see that all these things are really important, basic things that make your soil better. Chemical fertilizers will certainly give you fast growth, but they do nothing for the soil, leaving it to degrade. Organic material puts the soil first, which is where it should be, because it is a long-term resource, and vital, not just for the fun of good gardening, but for feeding the nation.

What Kinds of Organic Materials Are There?

Now we get to the practical stuff. What things can we use to add organic material to our soil or have it available for mulch. Here are some important sources: